Trying to add a tax function for liquidity into simple contract

Hello guys,
I'm fairly new to coding and solidity and was wondering if you could be gentle and help me out a little. I was wondering how I can add a tax function that will add liquidity with each transaction. This is what I have so far:

pragma solidity ^0.8.2;

contract Token {
mapping(address => uint) public balances;
mapping(address => mapping(address => uint)) public allowance;
uint public totalSupply = 10000 * 10 ** 18;
string public name = "";
string public symbol = "";
uint public decimals = 18;
uint256 public _taxFee = ;
uint256 private _previousTaxFee = _taxFee;
uint256 public _developmentFee = 0;
uint256 private _previousDevelopmentFee = _developmentFee;
uint256 public _liquidityFee = ;
uint256 private _previousLiquidityFee = _liquidityFee;

event Transfer(address indexed from, address indexed to, uint value);
event Approval(address indexed owner, address indexed spender, uint value);

constructor() {
    balances[msg.sender] = totalSupply;

function balanceOf(address owner) public returns(uint) {
    return balances[owner];

function transfer(address to, uint value) public returns(bool) {
    require(balanceOf(msg.sender) >= value, 'balance too low');
    balances[to] += value;
    balances[msg.sender] -= value;
   emit Transfer(msg.sender, to, value);
    return true;

function transferFrom(address from, address to, uint value) public returns(bool) {
    require(balanceOf(from) >= value, 'balance too low');
    require(allowance[from][msg.sender] >= value, 'allowance too low');
    balances[to] += value;
    balances[from] -= value;
    emit Transfer(from, to, value);
    return true;   

function approve(address spender, uint value) public returns (bool) {
    allowance[msg.sender][spender] = value;
    emit Approval(msg.sender, spender, value);
    return true;